Heidelberg 2015 – wissenschaftliches Programm
A 35.13: Poster
Donnerstag, 26. März 2015, 17:00–19:00, C/Foyer
Identification of EUV 5s–5p transitions in Re, Os, Ir, and Pt — •Hendrik Bekker1, Oscar O. Versolato1, Alexander Windberger1, Natalia S. Oreshkina1, Ruben Schupp1, Zoltán Harman1, Christoph H. Keitel1, Piet O. Schmidt2,3, and José R. Crespo López-Urrutia1 — 1Max-Planck-Institut für Kernphysik, Heidelberg — 2Physikalisch-Technische Bundesanstalt, Braunschweig — 3Institut für Quantumoptik, Leibniz Universität Hannover
Despite recent theoretical and experimental investigations of 5s–5p resonance lines in promethium-like highly charged ions near the 4f–5s level crossing, the transitions were never unambiguously identified yet [1,2]. To resolve this issue we studied the Pm-like and neighboring isoelectronic sequences spanning Re, Os, Ir, and Pt (Z=75–78) produced in the Heidelberg electron beam ion trap. The spectra obtained in the extreme ultra-violet (EUV) region around 20 nm were compared to collisional radiative model calculations which allowed us to identify the 5s–5p transitions and additional 5s2-5s5p transitions. Independent configuration interaction calculations support our identifications. Understanding the 4f–5s level crossing is of particular importance for future searches for a possible fine structure constant variation, and future optical clocks.
 U. I. Safronova, A. S. Safronova, and P. Beiersdorfer, Phys. Rev. A 88, 032512 (2013)
 Y. Kobayashi et al., Phys. Rev. A 89, 010501 (2014)